My Ranger had the factory surround sound speakers (two door speakers and two rear speakers in the extended cab). Sounded pretty good stock, but then I rigged up a pair of 12" subs and a 200w x1 channel rms amp (400w peak) to work off of my stock head unit. Made a lot of people scratch their heads over that one because it sounded so great (my one buddy had a totally aftermarket stereo in his car - Alpine 12" subs, Bazooka 400w rms amp, Sony Xplod speakers and head unit - mine was louder and clearer).
Later I did change to a high-end Pioneer HU, 915w x2 RMS amp (Rockford Fosgate FTW!), and a pair of 12" RF subs, but I kept the stock speakers. Sounded great and was LOUD. I kinda miss it even though I didn't crank it much, the extra bass was nice.
My F-150 has a middle of the road Pioneer and Rockford Fosgate speakers front and rear. Sounds pretty good but no subs because I can't sacrifice the space behind my front seats. Still, that's a pretty decent stereo for a work truck.
BTW, IMHO Sony speakers, amps, subs and HUs are J-U-N-K. Seen waaaayyy too many of them "xplode" for no reason. Also saw one of their amps die and start leaking green goo. Now I'm not an electrical engineer, but I do know a bit about electronics... and I still don't know of any electronics that should be leaking green goo.